Evaluation of Novel 7-(hetero)aryl-substituted Pyrazolo[1, 5-a]pyrimidines as Phosphodiesterase-4 Inhibitors

A novel series of 7-(hetero)aryl substituted-pyrazolopyrimidines, prepared via an AlCl3 induced C-C bond forming reaction of 7-chloro-5-phenyl-pyrazolo[1,5-a]pyrimidine with arenes and heteroarenes have been investigated as PDE4 inhibitors. Among all the compounds tested the 7-indolyl substituted pyrazolopyrimidine showed good inhibition of PDE 4 in vitro.